Jerry's technique works great. I also have good luck using a flywheel turning tool if the engine isn't seized up. It's a tool that does what Jerry describes with the wrecking bar, but it locks itself into the flywheel instead of having to use the bellhousing for leverage. If you search 'flywheel turning tool' on eBay, you'll get several hits.
If you have the engine out, consider using one of Jerry's kits to tap the crank snout so that you can install the harmonic balancer with a bolt. Sure makes it easier to turn over the engine using the bolt.
Matt
